In fields of engineering rotary motion of an actuator or mechanism is obtained by the use of a linear acting hydraulic or pneumatic ram acting on a linkage or mechanical arm about a pivoting axis.
Several problems exist with this means of obtaining rotary motion. Firstly, the space required to package the open-close movement of a linear acting ram is often large and undesirable. Secondly, the mechanical linkages involved limit the output rotation angle about the pivoting axis. Thirdly, the corresponding output torque about the pivoting axis varies dramatically depending upon the perpendicular component of force applied by the linear ram acting about the pivoting axis. And fourthly there are undesirable force vectors acting on the pivoting axis and surrounding components, requiring additional strengthening of such surrounding components.
The present invention provides a means of producing useful rotary motion in a compact manner and with a consistent and potentially high output torque.